Maidstone Crown Court heard Danai Muhammadi, 24, approached a mental health team after the break-up of his marriage to Melissa Crook, and may have been on anti-depressants.
Following his arrest in connection with the fire, police found a note on the windowsill of his house in Coventry saying: “Where can I get some help for my anger management? My wife has left me, can you help me get some counseling to help me repair my marriage? I’m very tired and unhappy.”
Police said they found a black notebook containing an emotional letter from Muham-madi to his toddler son Noah, written just a few weeks after the break-up, but which was never sent.
Muhammadi’s estranged wife Melissa, aged 20, their 15-month-old son Noah and his father-in-law, Mark, 50, died as a result of a blaze at their home in the early hours of September 10.
His mother-in-law Amanda, 50, and his brother-in-law Bohdan, 22, both survived by climbing out a window of the blazing home.
Muhammadi denies the three counts of murder and two of attempted murder.
His new girlfriend, Emma Smith, 21, and Farhad Mahmud, a 35-year-old bouncer, are accused of helping Muhammadi carry out the crime.
It is claimed Muhammadi and Mahmud, goaded by Smith, squirted petrol through the letter slot of the home and set it alight at the bottom of the stairwell, cutting off the main escape route from the house
Constable Ian Godsmark told the court he set off to tell Muhammadi his wife had died. But on the way to Coventry, he said Muhammadi became a suspect after his car was tracked going from Coventry to told the town where his wife lived before the fire.
Godsmark said: “Initially he said ‘What has happened to them?’
“He showed no sign of emotion at that stage.
“He appeared not to understand the word murder, and it was explained to him that it was when somebody had killed somebody else.
“He then began to cry and rubbed his eyes.
“After some 30 to 45 seconds, he sat up and said: ‘You may as well throw me in a cell and lock me away for life, I can’t live without them.’
“He looked up at the ceiling, took a deep breath, wiped his eyes and said: ‘I will not cry any more now’.”
The trial continues.